Table 2B.
Rejected terms for the biology and immunology of Echinococcus species.
| Word/expression | Definition | Reasons for rejection, references, linguistic clarifications | Comments |
|---|---|---|---|
| * Adult worm, Expression | Sexual reproduction stage Echinococcus spp. parasites in their definitive hosts. | Sometimes used as equivalent of “adult form”. | The expression was rejected by a majority of voters (median: 3). |
| Adult worm may be considered redundant, since worms are adult forms of helminths. | |||
| In addition, “adult form” in the definitive host corresponds to “larval form” in the intermediate host. | |||
| * Adventitia, Noun | Fibrous and cellular layer between the laminated layer of the hydatid in E. granulosus s.l. infection and the normal parenchyma of the host organ where the metacestode developed. | Word of Latin origin, “adventitia” is the outermost connective tissue covering of an organ, vessel, or other biological structure. In the CE cyst, this poorly cellular and mostly fibrous layer results from the host immune reaction to E. granulosus sensu lato metacestode. | As “adventitia” may be used for any biological structure, the use of “adventitial layer”, which refers to the parasite “germinal layer” and “laminated layer”, was preferred by the voters for this structure of host origin (median: 2, for “adventitia”). |
| * Boundary (periparasitic), Noun | Structures that surround the laminated layer of the hydatid of Echinococcus spp. metacestodes in their intermediate hosts, at the border with the organ parenchyma. | Alternative noun to “border”; “border” is more common in pathology terminology. | Rejected because of usage (median: 0). |
| * Died-out (cyst, lesion), Adjective | Non-viable parasitic structure as evidenced by imaging (complete calcification in AE, CE5 cyst in CE) or histological examination (absence of viable parasitic cells). | Could be used in clinical or experimental situations when evidence of absence of viability is not obtained by transplantation or in vitro culture. | Rejected by a majority of voters (median: 10, for rejection). |
| * Germinal cell, Expression | Pluripotent somatic stem cell with some homologies but also differences to neoblasts of free-living flatworms. Germinative cells are the only mitotically active cells in the metacestode and give rise to all differentiated cells. | Alternative expression to designate germinative cells. Same adjective as in the expression “germinal layer” where these cells are located. However, not all cells in the germinal layer correspond to this definition. | The germinal layer also contains other cell types such as muscle cells, nerve cells, and calcareous corpuscle-producing cells. This was an argument to reject the adjective “germinal” for such cells (median: 3). |
| Germinal membrane, Expression | Inner cellular layer of the Echinococcus spp. metacestode. | This term should be avoided and the term “layer” should be preferred because of the complexity of the various “layers” of the hydatid, and the possible confusion of “membrane” with the cell “membrane”, which has a specific definition in biology. | Germinal layer is the recommended expressions to designate the inner cellular “layer” of parasite origin in the Echinococcus spp. metacestode. |
| Hooklets, Noun | Appendices of the adult worm of Echinococcus spp. parasites allowing them to attach to the intestinal wall of the definitive hosts. | This term, a diminutive of “hooks”, is also used to designate these structures of the scolex and adult form of Echinococcus spp.; it should be avoided because the term “hooklet” infers a smaller version of a hook, i.e. that two forms are present, a larger “hook” and a smaller “hooklet” as in the haptor of some Monogenean parasites. | “Hook” is the only term recommended. |
| Hydatic, Adjective | Related to Echinococcus spp. | Gallicism for “hydatid” used as an adjective. | Should not be used in English. |
| * Infiltration (periparasitic), Noun | Histological components (cellular and fibrous) from host origin in alveolar echinococcosis | Alternative noun to “infiltrate”; infiltrate is more common in pathology terminology; infiltration has a slightly different meaning (systemic homing of inflammatory in the whole organ). | Rejected because of usage (median: 0). |
| Laminated membrane, Expression | Outer acellular layer of the Echinococcus spp. metacestode. | This term should be avoided and the term “layer” should be preferred because of the complexity of the various “layers” of the hydatid, and the possible confusion of “membrane” with the cell “membrane”, which has a specific definition in biology. | Laminated layer is the recommended expression to designate the outer acellular “layer” of parasite origin in the Echinococcus spp. metacestode. |
| Neoblast, Noun | Somatic stem cell type which shares homologies with germinative cells from Echinococcus spp. metacestodes, but also display significant differences. | Specific of planarians (and other free-living flatworms). | Should not be used for Echinococcus spp. |
| ** Non-fertile (adult form or worm), Expression | Adult form/worm of Echinococcus spp. whose last segment does not contain eggs. | Alternative to “immature” (adult form or worm). However, non-fertile could imply that this worm is not able to become fertile (which is wrong for the majority of adult Echinococcus spp. forms, especially in the definitive host in vivo). | In vitro-reared adult forms of Echinococcus spp. do not contain eggs; they exhibit some differences from the in vivo developed adult forms, and they are presumably non-fertile [56]. |
| However, the adjective “non-fertile” cannot be accepted for the usual situation of in vivo developed Echinococcus spp. adult forms/worms. | |||
| Primary cells, Expression | All cells that result from lytic digestion of the Echinococcus spp. metacestode and can be kept in culture using the “primary cell cultivation system”. | “Primary cell” is not a specific cell type of Echinococcus spp. metacestode, but a “culture system” [70]. | Primary cells are a mixture of “germinative cells” (~80% at the beginning), muscle cells and nerve cells [45]. |
| * Proglottid, Noun (singular), Proglottids (plural), Noun | Orthographic variant of “proglottis”: part of the adult form of Echinococcus spp. parasites resulting from segmentation of the scolex in the intestine of definitive hosts. | Proglottid is an alternative to proglottis in several dictionaries; the plural “proglottids” is commonly used in the USA (American English). Referring to the Greek origin of the word, “proglottis (sing), proglottides (plur) should be preferred. | This spelling was rejected by a majority of voters (7/10; median: 3) |
| Protoscolices (Plural of protoscolex), Noun | Prefiguration (“proto”) of the “scolex”, produced by the brood capsules budding from the germinal layer of Echinococcus spp. metacestode and released in the cyst fluid. | From the ancient Greek “σκὠλεξ”-scolex (worm), genitive: σκὠλεκος -scolecos, and not -scolicos; the plural form is σκὠλεκες, scoleces, and not scolices; with the prefix “πρῶτος”-protos (first/before). | Protoscoleces is the correct plural form, according to the etymology of the word. |
| Scolices (Plural of scolex), Noun | First segment (“head”) of the adult form of cestodes. | From the ancient Greek “σκὠλεξ”-scolex (worm), genitive: σκὠλεκος -scolecos, and not -scolicos; the plural form is σκὠλεκες, scoleces, and not scoleces. | Scoleces is the correct plural form, according to the etymology of the word. |
| Totipotent somatic stem cell, Expression | Stem cells in the germinal layer of Echinococcus spp. metacestode. | Alternative to “germinative cells”; however, the real totipotent cell, with specific markers, has not been identified yet [45]. | Pending a better definition of the really totipotent cells in the germinal layer of Echinococcus spp. metacestode, a single expression “germinative cell” should be kept. |
| * Transitional larva, Expression | Stage of Echinococcus spp. between the oncosphere and the fully developed hydatid (i.e. first stage in the metacestode development). | Alternative expression to “post-oncospheral” stage, but less precise to qualify a stage of a metacestode since it may apply to any larva. In addition, “transitional” may qualify any other stages of development (e.g. when brood capsules produce protoscoleces). | Rejected by all voters but 2 (median: 0). |
*
Agreement to reject the term obtained at the second stage of the consultation (the participants in the Consultation and Rating Group had to rate their approval or rejection of the words/expressions independently on a scale from 0 to 10; whenever relevant, the median of the votes is given in the “Comments” column).
**
Agreement to reject a term that was not selected at the first stage of consultation; the agreement was obtained at the second stage after further discussion between experts or after recommendation by the RRG.